The present invention relates generally to a braking apparatus for use in motor vehicles, and more particularly to such a braking apparatus with a control system for controlling the operating pattern of pressure control valves provided between a wheel braking cylinder and a master cylinder or an accumulator.
Generally, a braking apparatus for use in a motor vehicle comprises a master cylinder for generating a hydraulic pressure in response to depression of a braking pedal of the motor vehicle, an accumulator for accumulating a hydraulic pressure to a predetermined value, and at least one wheel braking cylinder for applying a braking force to a wheel of the motor vehicle. The wheel braking cylinder is coupled through pressure control valves to the master cylinder and the accumulator to perform the braking control for the wheel. The control valves may be required, due to relating to the braking action of the motor vehicle, to be checked in terms of normal opening and closing operations at a predetermined timing before running start such as on start of the engine. At the time of this operation checking (so-called primary check), when the valve between the accumulator and the wheel cylinder is opened, the pressure in the accumulator is supplied to the wheel braking cylinder side. Thereafter, the communication between the accumulator and the wheel braking cylinder is cut off and the wheel braking cylinder is then communicated with the master cylinder. At this time, the high-pressure remaining in the passage system to the wheel braking cylinder is rapidly transmitted to the master cylinder and this rapid high-pressure transmission allows generation of noises and causes the vehicle drive to be subject to a strong kickback when depressing the braking pedal.